Diesel Data: Automotive Repair

A/C Cycling Switch

A/C CYCLING SWITCH

NOTE: It is not necessary to recover the refrigerant before removing the A/C cycling switch.

The A/C cycling switch (ACCS) is used to prevent icing of the evaporator core by cycling OFF the A/C compressor clutch when the suction pressure in the low-pressure side of the refrigerant system drops below acceptable levels. The PCM monitors the A/C cycling switch (and dual-function pressure switch on 4.6L and 5.4L vehicles) through the ACCS circuit. When the ACCS circuit is open, the PCM will disengage the A/C compressor clutch. For specifications regarding operating pressure(s), refer to Heating and Air Conditioning.